Arylthiovinylcyclopropanecarboxylate intermediates

ABSTRACT

Arylthiovinylcyclopropanecarboxylates having the general formula ##STR1## are disclosed. The insecticidal efficacy and preparation of the compounds and novel intermediates therefor are also described and exemplified.

This is a division of application Ser. No. 872,413, filed Jan. 26, 1978.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a novel cyclopropanecarboxylateinsecticide, to an insecticidal method and composition and to newintermediates in the preparation of this insecticide. More particularly,the invention relates to the preparation and insecticidal use of certainarylthiovinylcyclopropanecarboxylates.

2. Prior Art

Pyrethrins, naturally occurring extracts of chrysanthemum flowers, havelong been of interest as insecticides. Since elucidation of thestructures of these compounds, synthesis efforts have been directedtoward preparation of related compounds having enhanced insecticidalactivity and improved stability toward air and light. A noteworthyadvance in this area was the discovery by Elliott, et al. of certainhighly active compounds remarkably resistent to photo-oxidativedegradation, for example, 3-phenoxybenzyl3-(β,β-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate. This class ofcompounds is set forth in U.S. Pat. No. 4,024,163, issued May 17, 1977.

Since the discovery by Elliott, et al., there has been extensiveresearch activity conducted in this area of insecticide chemistry. Onesuch effort is disclosed in Belgian Pat. No. 851,465, published Aug. 16,1977, which discloses certain phenylvinylcyclopropanecarboxylates asinsecticides. In addition, U.S. Pat. Nos. 3,723,649 and 3,786,052disclose certain other derivatives of vinyl cyclopropanecarboxylates andcarboxylic acids.

In spite of the intensity of effort in this field, thephenylthiovinylcyclopropanecarboxylates have not been described prior tothe present invention.

It has been found that these compounds are highly active insecticides,that they exhibit remarkable activity against insects of the ordercoleoptera and that they have excellent photo-stability.

SUMMARY OF THE INVENTION

The present invention comprises compounds of the formula ##STR2##wherein the groups R, Y and Z and the integer n are as described below.The insecticidally active members are those in which R represents thegroup--OR¹ wherein R¹ is as defined below. The invention also includesintermediates for these compounds in which R is halogen, hydroxy orlower alkoxy. An insecticidal composition and method is also provided.

DETAILED DESCRIPTION OF THE INVENTION

The compounds of this invention are those of formula I in which Y isindependently halogen, cyano, lower alkyl, lower haloalkyl, loweralkoxy, or lower alkylthio and n is an integer having a value of 0, 1, 2or 3; Z is hydrogen, halogen, cyano, or lower alkyl; and R is halogen,hydroxy, lower alkoxy, or --OR¹ wherein R¹ is allethrolonyl,tetrahydrophthalimidomethyl, or is represented by the formula ##STR3##in which R² is hydrogen, lower alkyl, cyano, ethynyl or trihalomethyl;R³ is divalent oxygen, divalent sulfur or vinylene; R⁴ and R⁵ areindependently hydrogen, lower alkyl, phenyl, phenoxy, benzyl, phenylthioor are joined to form a divalent methylenedioxy group attached to twoadjacent ring carbon atoms of a phenyl ring.

Throughout the specification the term "lower", as applied to an alkylgroup means having 1-6 carbon atoms, preferably 1-4 carbon atoms, andthe term "halo" or "halogen" means a bromine, chlorine, fluorine, andiodine, advantageously bromine, chlorine, and fluorine, preferablybromine and chlorine. These meanings are used throughout thespecification except where a contrary meaning is clearly indicated.

In accordance with the present invention the insecticidalphenylthiovinylcyclopropanecarboxylates are those of formula I in whichR is --OR¹, defined above, whereas the intermediates for theseinsecticidal phenylthiocyclopropanecarboxylates are compounds of formulaI in which R is halogen, hydroxy or lower alkoxy.

R¹ thus represents, for the insecticidal compounds, known alcoholresidues which have heretofore been used in the cyclopropanecarboxylateinsecticide art to produce insecticidally active compounds. The morereadily available of these alcohol groups include those in which R¹ is3-phenoxybenzyl, α-cyano-3-phenoxybenzyl,α-trihalomethyl-3-phenoxybenzyl and 5-benzyl-3-furylmethyl. Thepreferred compounds are thus esters which contain these alcoholresidues.

Also in a preferred embodiment Z is hydrogen or halogen, particularlychloro or bromo, and Y is hydrogen or halogen, particularly chloro orfluoro.

The compounds of this invention may be prepared in accordance with theillustrative examples set forth below. While the invention isillustrated by preparation of compounds having the cis,trans-E,Zconfiguration, it is understood that the present invention contemplatesand includes all possible isomeric configurations of the compounds.

In the examples which follow, unless a contrary intent is expressed,temperatures are in degrees centigrade, pressure is in mm Hg and liquidconcentration is performed under reduced pressure produced by a wateraspirator.

EXAMPLE 1 Synthesis of 3-phenoxybenzylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateA. Preparation of ethylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateas an intermediate

A mixture of 40.0 grams (0.095 mole) of(phenylthio)-methyltriphenylphosphonium chloride in 200 ml of benzene,was stirred under a nitrogen atomosphere at 0° C. for 10 minutes. Anequivalent (51 ml, 1.89 Molar, 0.095 mole) of n-butyllithium was addeddropwise to the reaction mixture over a period of 30 minutes whilemaintaining the 0° C. reaction mixture temperature. Following additionthe reaction mixture was stirred for 30 minutes at 0°-5° C., thensiphoned into a chilled (0° C.), stirred solution of 16.2 grams (0.095mole) of caronaldehyde in benzene. The reaction mixture was allowed towarm to ambient temperature for 2 hours, was then filtered and thefiltrate washed successively with two 80 ml portions of water, 60 ml ofa saturated aqueous solution of sodium bisulfite and 100 ml of asaturated aqueous solution of sodium chloride. The organic layer wasdried with magnesium sulfate and filtered. The filtrate was evaporatedunder reduced pressure to a residue which then was dissolved in a smallamount of diethyl ether. Upon standing, crystalline triphenylphosphineoxide precipitated from the solution. The mixture was filtered and thefiltrate was evaporated under reduced pressure to a residue which waspurified by vacuum distillation using a short-path Kugelrohrdistillation system. The distillate was further purified by elutionthrough a silicic acid cone (100 grams) with petroleum ether and asecond vacuum distillation using the short-path Kugelrohr distillationsystem, to give 14.0 grams (53.2%) of ethylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate.

B. Preparation ofcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid as an intermediate

To a stirred solution of 13.0 grams (0.047 mole) of ethylcis,trans-3[-2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylatein 50 ml of ethanol was added in one portion of a solution of 3.3 gramsof potassium hydroxide in 10 ml of water. The reaction mixture wasstirred at 40°-60° C. for 6 hours, then at ambient temperature for 18hours. The reaction mixture was evaporated under reduced pressure to aresidue which was dissolved in water and the solution extracted with 25ml of diethyl ether. The aqueous layer was acidified with concentratedhydrochloric acid and extracted twice with 75 ml, then 50 ml, of diethylether. The combined ether layers were dried with magnesium sulfate andfiltered. The filtrate was evaporated under reduced pressure to give11.2 grams (96%) ofcis,trans-3-[-2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid; m.p. 82°-96° C.

Analyses calc'd for C₁₄ H₁₆ O₂ S: C 67.71; H 6.50; Found: C 67.47; H6.58.

C. Conversion to 3-phenoxybenzylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate

A stirred solution of 3.4 grams (0.014 mole) ofcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid and 1.8 grams (0.015 mole) of thionyl chloride in 25 ml of benzenewas heated under reflux for 2 hours. The benzene and excess thionylchloride were removed by evaporation under reduced pressure, and 30 mlof fresh benzene was added to the acid chloride. The solution was cooledto 0°-5° C. and 1.2 grams (0.015 mole) of pyridine was added. Thereaction mixture was stirred at 0°-5° C. for 10 minutes and 2.7 grams(0.014 mole) of 3-phenoxybenzyl alcohol was added. A white precipitateformed almost immediately. The reaction mixture was warmed to ambienttemperature and stirred for 1 hour and filtered. The filtrate was washedwith 20 ml of 10% aqueous hydrochloric acid, 20 ml of 5% aqueous sodiumhydroxide, then 20 ml of saturated aqueous sodium chloride. The benzenelayer was dried with magnesium sulfate and filtered. The filtrate wasevaporated under reduced pressure to a residue which was purified byelution through an alumina cone (30 grams) with petroleum ether, then10% diethyl ether in petroleum ether, then 40% diethyl ether inpetroleum ether and finally with diethyl ether. The appropriatefractions were combined and evaporated under reduced pressure to give4.3 grams (74.7%) of 3-phenoxybenzylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate,as an oil. The nmr and the ir spectra were consistent with the assignedstructure.

Analyses calc'd for C₂₇ H₂₆ O₃ S: C 75.32; H 6.09; Found: C 75.53; H6.12.

EXAMPLE 2 Synthesis of α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate

A stirred solution of 4.7 grams (0.019 mole) ofcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid and 2.5 grams (0.02 mole) of thionyl chloride in 35 ml of benzenewas heated under reflux for 2 hours. The benzene and excess thionylchloride were removed by evaporation under reduced pressure. The acidchloride residue was combined with 3.0 grams (0.015 mole) of3-phenoxybenzaldehyde and added to a stirred, chilled (0° C.) solutionof 1.0 gram (0.02 mole) of sodium cyanide in 12 ml of tetrahydrofuranand 12 ml of water. The reaction mixture was stirred at 0°-20° C. for 2hours, then extracted with three portions, one 25 ml and two 40 ml, ofdiethyl ether. The combined ether extracts were washed with 40 mlaqueous sodium hydroxide solution and three times with 40 ml of water.The ether layer was dried with magnesium sulfate and filtered. Thefiltrate was evaporated under reduced pressure to a residue which wasredissolved in fresh diethyl ether and stirred for 6 hours at ambienttemperature with aqueous saturated sodium bisulfite. The ether layer wasseparated and dried with magnesium sulfate and filtered. The filtratewas evaporated under reduced pressure to a residue which was purified byelution through an alumina cone (35 grams) using petroleum ether, 5%diethyl ether in petroleum ether, 20% diethyl ether in petroleum ether,40% diethyl ether in petroleum ether, then with diethyl ether. Theappropriate fractions were combined and evaporated under reducedpressure to give 4.2 grams (62.2%) of α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate,as an oil. The nmr and ir spectra were consistent with the assignedstructure.

Analyses calc'd for C₂₈ H₂₅ NO₃ S: C 73.83; H 5.53; N 3.07; Found: C73.59; H 5.59; N 3.03.

EXAMPLE 3 Synthesis of α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateA. Preparation of phenylthiomethyl chloride as an intermediate

With stirring, 37.5 grams (1.25 moles) of paraformaldehyde was added to250 ml of benzene. To the benzene-paraformaldehyde mixture 500 ml ofconcentrated hydrochloric acid was added slowly at ambient temperature.The mixture was then heated at 31° C. for 30 minutes, and 110 grams ofthiophenol was added. Upon complete addition the reaction mixture washeated at 50°-55° C. for 2 hours, then allowed to cool to ambienttemperature where it stood for 18 hours. The reaction mixture wasseparated and the organic layer washed with 250 ml of water. The waterwash was extracted with 250 ml of benzene and the two benzene layerswere combined. The benzene combination was washed with 300 ml of aqueoussaturated sodium chloride, dried with magnesium sulfate and filtered.The filtrate was evaporated under reduced pressure to a residue whichwas further evaporated under high vacuum and distilled to give 115.9grams (73.2%) of phenylthiomethyl chloride; b.p. 80° C./3 mm. The nmrand the ir spectra were consistent with the assigned structure.

B. Preparation of diethyl phenylthiomethylphosphonate as an intermediate

A stirred solution of 40.0 grams (0.25 mole) of phenylthiomethylchloride and 58.2 grams (0.35 mole) of triethylphosphite was heated at150°-160° C. for 4 hours, cooled and excess triethylphosphite removed byevaporation under reduced pressure. The residue was purified bydistillation to give 61.1 grams (93.1%) of diethylphenylthiomethylphosphonate; b.p. 155° C./0.6 mm. The nmr and the irspectra were consistent with the assigned structure.

Analyses calc'd for C₁₁ H₁₇ O₃ PS: C 50.75; H 6.58; Found: C 50.54; H6.62.

C. Preparation of ethylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateas an intermediate

A solution of 16.4 grams (0.063 mole) of diethylphenylthiomethylphosphonate in 150 ml of tetrahydrofuran, under anitrogen atmosphere, was cooled to -78° C. where it stirred for 30minutes. After this time 33.9 ml (0.063 mole-1.87 Molar) ofn-butyllithium was added dropwise from a syringe, keeping the reactionmixture temperature below -60° C. Upon complete addition the reactionmixture was recooled to -78° C., where it was stirred for 15 minutes. Asolution of 9.7 grams (0.063 mole) of carbon tetrachloride in 40 ml oftetrahydrofuran was then added dropwise. The reaction mixture wasstirred for 15 minutes, then a solution of 9.8 grams (0.058 mole) ofcaronaldehyde in 40 ml of tetrahydrofuran was added dropwise. Thereaction mixture stirred at -78° C. for 15 minutes then allowed to warmto ambient temperature where it was stirred for 16 hours. Solvent wasremoved from the reaction mixture by evaporation under reduced pressure,the residue slurried in 50 ml of water, and the slurry extracted with100 ml and 25 ml of diethyl ether. The combined extracts were washedwith 75 ml of aqueous saturated sodium chloride. The ether layer wasdried with magnesium sulfate, the mixture filtered and the filtrateevaporated under reduced pressure to a residue. The residue was purifiedby passing it through a cone of silicic acid (100 grams) using petroleumether, then 10% methylene chloride-petroleum ether, as eluents.Fractions homogeneous when subjected to thin layer chromatography (TLC)were combined and evaporated under reduced pressure to a residue. Theresidue was further purified by a second passage through a cone ofsilicic acid using petroleum ether, then 10% methylene chloride inpetroleum ether as eluents. Fractions homogeneous when subjected to TLCwere combined and evaporated under reduced pressure to a residue. Theresidue was taken up in diethyl ether and dried with magnesium sulfate.The mixture was filtered and the filtrate was evaporated under reducedpressure to a residual oil. The residual oil was 9.1 grams (51%) ofethylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate.The nmr and the ir spectra were consistent with the assigned structure.

Analyses calc'd for C₁₆ H₁₉ ClO₂ S: C 61.82; H 6.16; Cl 11.41; Found: C61.92; H 6.17; Cl 11.32.

D. Preparation ofcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid as an intermediate.

This compound was prepared in the manner of Example 1.B., using 9.1grams (0.029 mole) of ethylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate,2.5 grams (0.044 mole) of potassium hydroxide in 30 ml of ethanol and 6ml of water. The yield of liquidcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid was 7.6 grams (91%). The nmr and the ir spectra were consistentwith the assigned structure.

E. Conversion to α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate

A solution of 4.6 grams (0.016 mole) ofcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid and 2.1 grams (0.018 mole) of thionyl chloride in 35 ml of benzenewas heated under reflux for 2 hours. Excess thionyl chloride and benzenewere removed by evaporation under reduced pressure to give the residualacid chloride. The acid chloride and 2.6 grams (0.013 mole) of3-phenoxybenzyaldehyde were simultaneously added dropwise to a stirredsolution of 0.9 gram (0.018 mole) of sodium cyanide in 10 ml oftetrahydrofuran and 10 ml of water and converted toα-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateas described in Example 2. The nmr and the ir spectra were consistentwith the assigned structure.

Analyses calc'd for: C₂₈ H₂₄ ClNO₃ S: C 68.63; H 4.94; Cl 7.24; N 2.86;Found: C 68.85; H 4.98; Cl 7.13; N 2.85.

EXAMPLE 4 Synthesis of 3-phenoxybenzylcis,trans-3-[2-(E,Z)chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate

A stirred solution of 3.4 grams (0.012 mole) ofcis,trans-3-[2-(E,Z)-chloro-2-phenylthiothenyl]-2,2-dimethylcyclopropanecarboxylicacid and 1.0 ml (0.014 mole) of thionyl chloride in 20 ml benzene washeated at reflux under a nitrogen atmosphere for 2 hours. The benzenesolvent was removed by distillation; 5 ml of benzene was added and thiswas removed by distillation. The reaction mixture was cooled to 40° C.and 5 ml of benzene was added. To this stirred mixture was added asolution of 2.4 grams (0.012 mole) of 3-phenoxybenzyl alcohol and 1.0 ml(0.012 mole) of pyridine in 5 ml of benzene. After addition was completethe reaction mixture was stirred under a nitrogen atmosphere for 4 hoursand was then diluted with 15 ml each of diethyl ether and water. Theorganic layer was separated and extracted with a 5% aqueous solution ofhydrochloric acid. The extract and the water layer were combined andbackwashed with diethyl ether. The ether wash and the organic layer werecombined and washed with aqueous solutions saturated with sodiumbicarbonate and sodium chloride. The organic layer was dried withmagnesium sulfate and filtered. The filtrate was evaporated underreduced pressure to a residue. The residue was taken up in 15 ml ofcarbon tetrachloride, stirred with 3 grams of powdered charcoal,filtered, and the filtrate evaporated under reduced pressure to aresidue. The residue was purified by column chromatography, the columnbeing 30 grams of silica gel. Elution was accomplished using petroleumether, then successively 1%, 2%, 5%, 7.5%, 10%, 15%, 20%, 30%, and 35%mixtures of methylene chloride in petroleum ether. The appropriatefractions were combined and evaporated under reduced pressure to give4.0 grams (72%) of 3-phenoxybenzylcis,trans-3-[2-(E,Z)-2-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateas a liquid. For analytical purposes, a small sample was distilled underreduced pressure; b.p. 150° C./0.04 mm. The nmr spectra were consistentwith the assigned structure.

Analyses calc'd for C₂₉ H₂₅ ClO₃ S: C 69.73; H 5.42; C 17.63; Found: C69.58; H 5.44; C 17.59.

EXAMPLE 5 Synthesis of 3-phenoxybenzylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylateA. Preparation of 4-fluorophenylthiomethyl chloride as an intermediate

This compound was prepared in the manner of Example 3.A., using 45.0grams (0.35 mole) of a 4-fluorothiophenol, 13.5 grams (0.44 mole) ofparaformaldehyde and 180 ml (1.8 moles) of concentrated hydrochloricacid in 90 ml of benzene. The residue was distilled under reducedpressure to give 61.9 grams (99.8%) of 4-fluorophenylthiomethylchloride; b.p. 65° C./0.5 mm.

Analyses calc'd for C₇ H₆ ClFS: C 47.59; H 3.42; Cl 20.07; Found: C47.69; H 3.48; Cl 20.09.

B. Preparation of diethyl 4-fluorophenylthiomethylphosphonate as anintermediate

This compound was prepared in the manner of Example 3.B., using 59.3grams (0.34 mole) of 4-fluorophenylthiomethyl chloride and 71.3 grams(0.43 mole) of triethylphosphite. The residue was distilled underreduced pressure to give 89.4 grams (95.7%) of diethyl4-fluorophenylthiomethylphosphonate; b.p. 147° C./0.6 mm.

C. Preparation of ethylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylateas an intermediate

This compound was prepared in the manner of Example 3.C., using 41.0grams (0.15 mole) of diethyl 4-fluorophenylthiomethylphosphonate, 69.4ml (0.17 mole, 2.4 Molar) of n-butyllithium, and 25.0 grams (0.15 mole)of caronaldehyde in 650 ml of tetrahydrofuran, except that no carbontetrachloride was used. The residue was purified by distillation underreduced pressure using a short path Kugelrohr distillation system, togive 32.7 grams (75.3%) of ethylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylateas an oil. The nmr and the ir spectra were consistent with the assignedstructure.

Analyses calc'd for C₁₆ H₁₉ FO₂ S: C 65.28; H 6.51; Found: C 65.41; H6.55.

D. Preparation ofcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylicacid as an intermediate

This compound was prepared in the manner of Example 1.B., using 36.2grams (0.12 mole) of ethylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate,10.3 grams (0.18 mole) of potassium hydroxide in 100 ml of ethanol and25 ml of water. The weight of crude liquidcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylicacid was 29.3 grams (90.6%). The product was purified by passing itthrough a silicic acid cone using 40% diethyl ether in petroleum ether.The nmr and the ir spectra were consistent with the assigned structure.

Analyses calc'd for C₁₄ H₁₅ FO₂ S: C 63.13; H 5.68; Found: C 63.27; H5.73.

E. Conversion to 3-phenoxybenzylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate

This compound was prepared in the manner of Example 3, using 5.7 grams(0.021 mole) ofcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylicacid, 2.8 grams (0.023 mole) of thionyl chloride, 4.3 grams (0.021 mole)of 3-phenoxybenzyl alcohol, 1.9 grams (0.023 mole) of pyridine, and 100ml of benzene. The residue was purified by passing it through an aluminacone (50 grams) using petroleum ether, 10%, 20% methylene chloride inpetroleum ether, and methylene chloride as eluents. The appropriatefractions were combined and evaporated under reduced pressure to give7.2 grams (75%) of 3-phenoxybenzylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylateas a liquid. The nmr and the ir spectra were consistent with theassigned structure.

Analyses calc'd for C₂₇ H₂₅ FO₃ S: C 72.30; H 5.62; Found: C 72.22; H5.68.

EXAMPLE 6 Synthesis of α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate

This compound was prepared in the manner of Example 2, using 6.9 grams(0.026 mole) ofcis,trans-3-[2(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylicacid, 3.4 grams (0.028 mole) of thionyl chloride, 1.4 grams (0.029 mole)of sodium cyanide, 4.2 grams (0.021 mole) of 3-phenoxybenzaldehyde, 60ml of benzene, 20 ml of tetrahydrofuran, and 20 ml of water. The residuewas purified by passing it through an alumina cone (45 grams) using aseluents 5%, 10%, and 20% methylene chloride in petroleum ether, andmethylene chloride. The appropriate fractions were combined andevaporated under reduced pressure to give 6.6 grams (66.6%) ofα-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylateas a liquid. The nmr and the ir spectra were consistent with theassigned structure.

Analyses calc'd for C₂₈ H₂₄ FNO₃ S: C 71.01; H 5.11; N 2.96; Found: C70.92; H 5.20; N 2.85.

EXAMPLE 7 Synthesis of α-trifluoromethyl-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate

This compound was prepared in the manner of Example 1.C., using 3.0grams (0.011 mole) ofcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylicacid, 1.4 grams (0.012 mole) of thionyl chloride, 2.8 grams (0.011 mole)of α-trifluoromethyl-3-phenoxybenzyl alcohol, 0.92 gram (0.012 mole) ofpyridine, and 60 ml of benzene. The residue was purified by passing itthrough an alumina cone (24 grams) using as eluents petroleum ether, and20% diethyl ether in petroleum ether. The appropriate fractions werecombined and evaporated under reduced pressure to give 2.8 grams (48.4%)of α-trifluoromethyl-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylateas a liquid. The nmr and the ir spectra were consistent with theassigned structure.

Analyses calc'd for C₂₈ H₂₄ ClF₃ O₃ S: C 63.09; H 4.54; Cl 6.65; Found:C 62.87; H 4.58; Cl 6.57.

The following were also prepared in accordance with the foregoingexamples.

EXAMPLE 8 α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate

Analyses calc'd for C₂₈ H₂₃ ClFNO₃ S: C 66.17; H 4.56; N 2.75; Found: C66.14; H 4.59; N 2.74.

EXAMPLE 9 3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-(4-chlorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate

Analyses calc'd for C₂₇ H₂₄ Cl₂ O₃ S: C 64.92; H 4.70; Cl 14.19; Found:C 64.18; H 4.99; Cl 14.48.

EXAMPLE 10 3-phenoxybenzylcis,trans-3-[2-(E,Z)-bromo-2-phenylthioethenyl]-2,2-dimethylcyclopropanecarboxylate

Analyses calc'd for C₂₇ H₂₀ BrO₃ S: C 63.52; H 5.13; Found: C 63.12; H5.38.

EXAMPLE 11 3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-(4-fluorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate

Analyses calc'd for C₂₇ H₂₅ ClFO₃ S: C 66.71; H 5.18; Found: C 66.99; H5.20.

EXAMPLE 12 α-cyano-3-phenoxybenzylcis,trans-3-[2-(E,Z)-chloro-2-(4-chlorophenylthio)ethenyl]-2,2-dimethylcyclopropanecarboxylate

Analyses calc'd for C₂₈ H₂₃ Cl₂ O₃ NS: C 64.12; H 4.40; N 2.67; Found: C64.32; H 4.50; N 2.67.

It will be apparent to one skilled in the pyrethroid art that theappropriately substituted lower alkyl ester (R is alkoxy in formula I)may also be transesterified directly to produce the insecticidalcompounds, rather than proceeding through hydrolysis of the lower alkylester, formation of the acid chloride and conversion of the acidchloride.

In the method of this invention an effective insecticidal amount of thecompound is applied to the locus where insect control is desired,usually to the foliage or seeds of agricultural plants. The compound maybe applied as technical material or as a formulated product. Typicalformulations include compositions of the active ingredient incombination with an agriculturally acceptable carrier or extender,preferably with a surface-active agent, and optionally with other activeingredients. Suitable formulations include granules, powders, orliquids, the choice varying with the type of pests and environmentalfactors present at the particular locus of infestation. Thus, thecompounds may be formulated as granules of various sizes, as dusts, aswettable powders, as emulsifiable concentrates, as solutions, asdispersions, as controlled release compositions, and the like. A typicalformulation may vary widely in concentration of the active ingredientdepending upon the particular agent used, the additives and carriersused, other active ingredients, and the desired mode of application.With due consideration of these factors, the active ingredient of atypical formulation may, for example, be suitably present at aconcentration of about 0.5% up to about 99.5% by weight of theformulation. An agriculturally acceptable carrier may comprise about99.5% by weight to as low as about 0.5% by weight of the formulation.Compatible surface-active agents, if employed in the formulation, may bepresent at various concentrations, suitably in the range of 1% to 30% byweight of the formulation.

The formulation may be used as such or diluted to a desired use dilutionwith a diluent or carrier suitable for facilitating dispersion of theactive ingredients. The concentration of the active ingredient in usedilution is normally in the range of about 0.001 to about 5% by weight.Many variations of spraying, dusting, and controlled or slow releasecompositions in the art may be used by substituting or adding a compoundof this invention into compositions known or apparent to the art.

The compounds of this invention may be formulated and applied with othercompatible active ingredients, including nematicides, insecticides,acaricides, fungicides, plant regulators, herbicides, fertilizers, etc.

In applying these compounds, whether alone or with other agriculturalchemicals an effective insecticidal amount of the active ingredient mustbe applied. While the application rate will vary widely depending on thechoice of compound, the formulation and mode of application, the plantspecies being protected, and the planting density, a suitable use ratemay be in the range of about 0.05 to 5 kg./hectare, preferably 0.1 toabout 2 kg./hectare.

The compounds of this invention were tested for initial insecticidalactivity and seven day residual activity as described below.

EXAMPLE 13 Toxicity to Insects and Mites

Initial Contact Activity:

The test compound was dissolved in a small amount of acetone, and theacetone solution was dispersed in water containing one drop ofisooctylphenyl polyethoxyethanol to make a solution having 1250 ppm(w/w) active ingredient. Aliquots of this solution were diluted with anappropriate amount of water to provide solutions containing variousconcentrations of active ingredient. Test organisms and techniques wereas follows: the activity against Mexican bean beetle (Epilachnavarivestis Muls.) and southern armyworm (Spodoptera eridania [Cram.])was evaluated by dipping the leaves of pinto bean plants into the testsolution and infesting the leaves with the appropriate immature-forminsects when the foliage had dried. The activity against the pea aphid(Acyrthosiphon pisum [Harris]) was evaluated on broad bean plants whoseleaves were dipped before infestation with adult aphids. The activityagainst twospotted spider mites (Tetranychus urticae Koch) was evaluatedon pinto bean plants whose leaves were dipped after infestation withadult mites. The activity against the milkweed bug (Oncopeltus faciatus[Dallas]) was evaluated by spraying the test solutions into glass dishesor jars containing the adult insects. Following application of thecompound and infestation the tests were maintained in a holding room at80° F. and 50% relative humidity for an exposure period of 72 hours. Atthe end of this time the dead and living insects or mites were countedand the percent kill was calculated. Results of these tests aresummarized in Table I. Most of the compounds tested were active againstall the insects. A number of them showed remarkable activity against themilkweed bug and Mexican bean beetle even at extremely lowconcentrations.

Residual Contact Activity:

The residual contact activity of certain of the compounds was determinedon the same organisms using the techniques described above, except thatin each case the treated surface was allowed to dry and was exposed tonormal light and air for seven days before introduction of the mites orinsects. Results of these tests are summarized in Table II. The sevenday residual activity was minimal for the mite but substantial againstthe remaining organisms. Again, the remarkable activity of some of thesecompounds against milkweed bug and Mexican bean beetle was noted.

                  TABLE I                                                         ______________________________________                                        INITIAL ACTIVITY                                                              Compound                                                                              Conc.     Percent Kill                                                of Example                                                                            ppm.      MWB*    MBB*  AW*   PA*   SM*                               ______________________________________                                        1       1250      30      100   0     0     0                                         312       5       --    --    0     0                                         78        10      62    0     0     0                                         20        10      0     0     0     0                                         5                 28    0                                                     1.2               44    0                                                     Untreated 5       0     0     0     5                                 2       1250      100     100   41    75    0                                         312       90                  5     0                                         78        20      80    0     0     0                                         20        0       22    0     0     0                                         5                 0     0                                                     1.2               6     0                                                     Untreated 5       0     0     0     5                                 3       1250      100     94    100   100   49                                        312       100                 85    0                                         78        100     92    75    60    0                                         20        70      92    0     27    0                                         5                 100   0                                                     1.2               80    0                                                     Untreated 5       0     0     0     5                                 4       1250      100     95    100   100   42                                        312       90      100   89    100   31                                        78        10      100   68    75                                              20                94    0                                                     5                 100   11                                                    Untreated 0       0     0     0     2.9                               5       1250      15            7     35    0                                         312       5       95    0     45    0                                         78        0       35    0     0     0                                         20                33                                                          5                                                                             1.2                                                                           Untreated 4.8     0     0     0     2.3                               6       1250      100           56    100   0                                         312       38      100   0     10    0                                         78        5       94    0     0     0                                         20                68                                                          5                                                                             1.2                                                                           Untreated 4.8     0     0     0     2.3                               7       1250      100           0     100   62                                        312       32      100   0     100                                             78        5       100   0     94                                              20                90                                                          Untreated 5       0     0     0     6                                 8       1250      100           90    93    100                                       312       100     100   80    94                                              78        75      100   40    46                                              20                100                                                         Untreated 0       0     0     0     6                                 9       1250      90            20    100   0                                         312       70      100   0     100                                             78        0       100   0     71                                              20                100                                                         Untreated 0       0     0     0     6                                 10      1250      100           100   95    81                                        312       71      94    44    94                                              78        5       95    0     24                                              20                72                                                          Untreated 10      0     0     0     8                                 ______________________________________                                         *See footnote, Table II.                                                 

                  TABLE II                                                        ______________________________________                                        7-DAY RESIDUAL ACTIVITY                                                       Compound                                                                              Conc,     Percent Kill                                                of Example                                                                            ppm.      MWB.sup.1                                                                             MBB.sup.2                                                                           AW.sup.3                                                                            PA.sup.4                                                                            SM.sup.5                          ______________________________________                                        1       1250      0       --    0     30    0                                         312       10      --    0     10                                              78        5       --    0     0                                               20                      0                                                     Untreated 20      --    0     0     0                                 2       1250      5       --    0     100   0                                         312       0       --    0     23                                              78        5       --    0     30                                              20                      0                                                     Untreated 20      --    0     0     0                                 3       1250      100     97    100   100   0                                         312       85            53    65                                              78        70      100   56    50                                              39                100                                                         20                      62                                                    10                75                                                          2.5               66                                                          Untreated 20      3     0     0     0                                 4       1250      100     100   95    85    0                                         312       20      100   55    0                                               78                100   5                                                     20                89    0                                                     Untreated 5       0     0     0     0                                 ______________________________________                                         .sup.1 Milkweed bug                                                           .sup. 2 Mexican bean beetle                                                   .sup.3 Southern armyworm                                                      .sup.4 Pea aphid                                                              .sup.5 Twospotted spider mite                                            

I claim:
 1. A compound of the formula ##STR4## wherein Y isindependently halogen, cyano, lower alkyl, lower haloalkyl, lower alkoxyor lower alkylthio,n is 0, 1, 2, or 3, Z is hydrogen, halogen, cyano orlower alkyl, and R is halogen, hydroxy or lower alkoxy.